Hydrangea plant named ‘H218912’

ABSTRACT

A new and distinct cultivar of  Hydrangea  plant named ‘H218912’, characterized by its upright and uniformly mounded plant habit; vigorous growth habit and rapid growth rate; freely branching habit with strong, thick and sturdy stems; freely and uniformly flowering habit; mophead-type inflorescences with numerous red purple and yellow green-colored sterile flowers; and good postproduction longevity.

Botanical designation: Hydrangea macrophylla.

Cultivar denomination: ‘H218912’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar of Hydrangea plant, botanically known as Hydrangea macrophylla, commercially referred to as a mophead-type Hydrangea and hereinafter referred to by the name ‘H218912’.

The new Hydrangea plant is a product of a planned breeding program conducted by the Inventor in De Kwakel, The Netherlands and Lengerich, Germany. The objective of the breeding program was to create new strong and freely-branching Hydrangea plants with strong sturdy stems, uniform flowering habit, large inflorescences with numerous showy sterile flowers, attractive sterile flower color and good postproduction longevity.

The new Hydrangea plant originated from a cross-pollination made by the Inventor in March, 2013 in De Kwakel, The Netherlands, of a proprietary selection of Hydrangea macrophylla identified as code number 05-0126-008, not patented, as the female, or seed, parent with Hydrangea macrophylla ‘Green Shadow’, not patented, as the male, or pollen, parent. The new Hydrangea plant was discovered and selected by the Inventor as a single flowering plant from within the progeny of the stated cross-pollination in a controlled greenhouse environment in Lengerich, Germany in March, 2014.

Asexual reproduction of the new Hydrangea plant by vegetative tip cuttings in a controlled environment in De Kwakel, The Netherlands since April, 2015 has shown that the unique features of this new Hydrangea plant are stable and reproduced true to type in successive generations.

SUMMARY OF THE INVENTION

Plants of the new Hydrangea have not been observed under all possible combinations of environmental conditions and cultural practices. The phenotype may vary somewhat with variations in environmental conditions such as temperature and light intensity without, however, any variance in genotype.

The following traits have been repeatedly observed and are determined to be the unique characteristics of ‘H218912’. These characteristics in combination distinguish ‘H218912’ as a new and distinct Hydrangea plant:

-   -   1. Upright and uniformly mounded plant habit.     -   2. Vigorous growth habit and rapid growth rate.     -   3. Freely branching habit with strong, thick and sturdy stems.     -   4. Freely and uniformly flowering habit.     -   5. Mophead-type inflorescences with numerous red purple and         yellow green-colored sterile flowers.     -   6. Good postproduction longevity.

Plants of the new Hydrangea can be compared to plants of the female parent selection. Plants of the new Hydrangea differ primarily from plants of the female parent selection in sterile flower color as plants of the new Hydrangea have red purple and yellow green-colored sterile flowers whereas plants of the female parent selection have dark red-colored sterile flowers.

Plants of the new Hydrangea can be compared to plants of the male parent selection. Plants of the new Hydrangea differ primarily from plants of the male parent selection in growth habit as plants of the new Hydrangea are more compact than plants of the male parent selection.

Plants of the new Hydrangea can be compared to plants of the Hydrangea macrophylla ‘HBA215910’, disclosed in U.S. Plant Pat. No. 29,171. In side-by-side comparisons, plants of the new Hydrangea differ primarily from plants of ‘HBA215910’ in the following characteristics:

-   -   1. Plants of the new Hydrangea are broader and more vigorous         than plants of ‘HBA215910’.     -   2. Plants of the new Hydrangea have longer leaves than plants of         ‘HBA215910’.     -   3. Plants of the new Hydrangea have larger panicles than plants         of ‘HBA215910’.     -   4. Plants of the new Hydrangea have larger sterile flowers than         plants of ‘HBA215910’.     -   5. Plants of the new Hydrangea have red purple and yellow         green-colored sterile flowers whereas plants of ‘HBA215910’ have         dark red purple-colored sterile flowers with green-colored         sectors.     -   6. Plants of the new Hydrangea and ‘HBA215910’ differ in         reaction to aluminum sulfate treatment as sterile flower sepals         of plants of the new Hydrangea treated with aluminum sulfate         become red purple to purple violet and yellow green in color         whereas sterile flower sepals of plants of ‘HBA215910’ treated         with aluminum sulfate become light purple violet in color with         greyed red-colored sectors.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying colored photographs illustrate the unique appearance of the new Hydrangea plant showing the colors as true as it is reasonably possible to obtain in colored reproductions of this type. Colors in the photographs may differ from the color values cited in the detailed botanical description which accurately describe the colors of the new Hydrangea plant.

The photograph on the first sheet is a side perspective view of a typical flowering plant of ‘H218912’.

The photograph on the second sheet is a close-up view of a typical inflorescence of ‘H218912’.

The photograph on the third sheet is a top perspective view of a typical flowering plant of ‘H218912’ that has been “blued” (left) that is, treated with aluminum sulfate, and a top perspective view of a typical flowering plant of ‘H218912’ that has not been “blued” (right) that is, not treated with aluminum sulfate.

DETAILED BOTANICAL DESCRIPTION

Plants used in the aforementioned photographs and in the following description were grown during the late spring and early summer in 13-cm containers in a glass-covered greenhouse in De Kwakel, The Netherlands and under cultural practices typical of commercial Hydrangea production. During the production of the plants, day and night temperatures averaged 17° C. Plants of the new Hydrangea were one year old when the photographs and description were taken. Plants of the new Hydrangea can be successfully treated with aluminum sulfate to “blue” the inflorescences. In the following description, color references are made to The Royal Horticultural Society Colour Chart, 2015 Edition, except where general terms of ordinary dictionary significance are used.

-   Botanical description: Hydrangea macrophylla ‘H218912’. -   Parentage:     -   -   Female, or seed, parent.—Proprietary selection of Hydrangea             macrophylla identified as code number 05-0126-008, not             patented.         -   Male, or pollen, parent.—Hydrangea macrophylla ‘Green             Shadow’, not patented. -   Propagation:     -   -   Type cutting.—By vegetative tip cuttings.         -   Time to initiate roots, summer.—About two weeks at             temperatures about 23° C.         -   Time to initiate roots, winter.—About 18 days at             temperatures about 20° C.         -   Time to produce a rooted young plant, summer.—About four             weeks at temperatures about 23° C.         -   Time to produce a rooted young plant, winter.—About five             weeks at temperatures about 20° C.         -   Root description.—Thick; typically whitish brown in color,             actual color of the roots is dependent on substrate             composition, water quality, fertilizer type and formulation,             substrate temperature and physiological age of roots.         -   Rooting habit.—Freely branching; dense. -   Plant description:     -   -   Plant and growth habit.—Upright and uniformly mounded plant             habit; strong and sturdy stems; rapid growth rate and             vigorous growth habit.         -   Plant height.—About 25 cm to 30 cm.         -   Plant diameter or area of spread.—About 55 cm to 60 cm. -   Lateral branch description:     -   -   Branching habit.—Freely branching habit; when pinched, about             eight lateral branches develop per plant.         -   Length.—About 15 cm to 20 cm.         -   Diameter.—About 6 mm.         -   Internode length.—About 3 cm to 3.5 cm.         -   Texture.—Smooth, glabrous; fully developed, woody.         -   Aspect.—Upright to about 20° from vertical.         -   Strength.—Strong, sturdy.         -   Color.—When developing: Close to 146C; at internodes, close             to 187A; lenticels, close to 187A. Developed: Close to 146C;             at the internodes, close to 187A; when woody, close to 177D;             lenticels, close to 187A. -   Leaf description:     -   -   Arrangement.—Opposite, simple.         -   Length.—About 10 cm to 13 cm.         -   Width.—About 6 cm to 8 cm.         -   Shape.—Ovate.         -   Apex.—Acuminate to cuspidate.         -   Base.—Obtuse.         -   Margin.—Dentate to serrate.         -   Texture, upper and lower surfaces.—Rugose, glabrous.         -   Venation pattern.—Pinnate.         -   Color.—Developing and fully expanded leaves, upper surface:             Close to NN137B; venation, close to 145B. Developing and             fully expanded leaves, lower surface: Close to 138B;             venation, close to 145C.         -   Petioles.—Length: About 2 cm to 3 cm. Diameter: About 3 mm.             Texture, upper and lower surfaces: Smooth, glabrous. Color,             upper surface: Close to 145B. Color, lower surface: Close to             145C. -   Flower description:     -   -   Flower type and habit.—Showy sterile flowers and small             inconspicuous fertile flowers arranged on mophead-type             terminal panicles; panicles globular in shape; flowers face             upright to outwardly depending on their position in the             inflorescence.         -   Fragrance.—None detected.         -   Natural flowering season.—Plants begin flowering about one             year after planting; flowering begins in the early summer             and is continuous throughout the summer in Northern Europe.         -   Flower longevity.—Fertile flowers last about one month on             the plant, fertile flowers not persistent; sterile flowers             last about four months on the plant, sterile flowers             persistent.         -   Quantity of flowers.—Freely flowering habit; about 40             fertile flowers per panicle and about 80 sterile flowers per             panicle.         -   Panicle height.—About 6 cm to 10 cm.         -   Panicle diameter.—About 18 cm to 22 cm.         -   Fertile flower buds.—Length: About 3 mm. Diameter: About             3 mm. Shape: Flattened globular. Color: Close to 144D.         -   Sterile flower buds.—Length: About 3 mm. Diameter: About             3 mm. Shape: Flattened globular. Color: Close to 145A 63C.         -   Fertile flower diameter.—About 6 mm.         -   Fertile flower depth (height).—About 5 mm.         -   Sterile flower diameter.—About 6 cm to 7 cm.         -   Sterile flower depth (height).—About 1 cm.         -   Petals, fertile flowers.—Quantity and arrangement: Four in a             single whorl. Length: About 3.5 mm. Width: About 2 mm.             Shape: Ovate. Apex: Acute. Base: Obtuse. Margin: Entire.             Texture, upper and lower surfaces: Smooth, glabrous. Color:             When opening, upper surface: Close to N75C and 149D. When             opening, lower surface: Close to 145C. Fully opened, upper             and lower surfaces: Close to 72D; color does not change with             development.         -   Petals, sterile flowers.—Quantity and arrangement: Four to             five in a single whorl. Length: About 3 mm. Width: About             2 mm. Shape: Ovate. Apex: Acute. Base: Attenuate. Margin:             Entire. Texture, upper and lower surfaces: Smooth, glabrous.             Color: When opening, upper and lower surfaces: Close to             145D. Fully opened, upper and lower surfaces: Close to N57D;             color does not change with development.         -   Sepals, fertile flowers.—Quantity and arrangement: Five in a             single whorl. Length: About 2 mm. Width: About 2 mm. Shape:             Ovate. Apex: Acute. Base: Obtuse. Margin: Entire. Texture,             upper and lower surfaces: Smooth, glabrous. Color: When             opening and fully opened, upper surface: Close to 138A;             color does not change with development. When opening and             fully opened, lower surface: Close to 138B; color does not             change with development.         -   Sepals, sterile flowers.—Quantity and arrangement: Five in a             single whorl. Length: About 2 cm to 4 cm. Width: About 1.5             cm to 2 cm. Shape: Ovate. Apex: Acute. Base: Obtuse. Margin:             Entire. Texture, upper and lower surfaces: Smooth, glabrous.             Color: When opening, upper surface: Centers, close to 145A             and towards the margins and base, close to 63A. When             opening, lower surface: Centers, close to 145B and towards             the margins and base, close to 63B. Fully opened, upper             surface: Centers, close to 146A and towards the margins and             base, close to 63A; with development, color becoming closer             to 146A with edges, close to 176A; when “blued”, centers             become close to 146A and towards the margins and base, close             to 64A and N81A. Fully opened, lower surface: Centers, close             to 146C and towards the margins and base, close to 63B;             color does not change with development.         -   Pedicels, fertile flowers.—Length: About 1 cm. Diameter:             About 1 mm. Strength: Moderately strong. Aspect: Mostly             upright. Texture: Smooth, glabrous. Color: Close to 63A.         -   Pedicels, sterile flowers.—Length: About 2 cm to 2.5 cm.             Diameter: About 1.5 mm. Strength: Strong. Aspect: Erect to             about 45° from vertical. Texture: Smooth, glabrous. Color:             Close to 145B tinged with close to 63B.         -   Reproductive organs, fertile flowers.—Stamens: Quantity per             flower: Eight. Filament length: About 1 mm. Filament color:             Close to NN155D. Anther length: About 1 mm. Anther shape:             Conical. Anther color: Close to 145D. Pollen amount:             Abundant. Pollen color: Close to NN155D. Pistils: Pistil             quantity per flower: Three. Pistil length: About 1 mm.             Stigma shape: Oval. Stigma color: Close to 150D. Style             length: About 1 mm. Style color: Close to 69B. Ovary color:             Close to 69B.         -   Reproductive organs, sterile flowers.—Stamens: Quantity per             flower: Eight. Filament length: About 1 mm. Filament color:             Close to NN155D. Anther length: About 1 mm. Anther shape:             Conical. Anther color: Close to 145D. Pollen amount:             Abundant. Pollen color: Close to NN155D. Pistils: Pistil             quantity per flower: Three. Pistil length: About 1 mm.             Stigma shape: Oval. Stigma color: Close to 155C. Style             length: About 1 mm. Style color: Close to 150D. Ovary color:             Close to 150D.         -   Seeds, only produced by fertile flowers.—Quantity per             fertile flower: About 20 to 30. Length: About 0.5 mm.             Diameter: About 0.1 mm. Color: Close to 200C. -   Pathogen & pest resistance: Under commercial production conditions,     plants of the new Hydrangea have not been observed to be resistant     to pathogens and pests common to Hydrangea plants to date. -   Temperature tolerance: Plants of the new Hydrangea have been shown     to be tolerant to temperatures ranging from about 3° C. to about 38°     C. 

It is claimed:
 1. A new and distinct Hydrangea plant named ‘H218912’ as illustrated and described. 